Certain operators or access providers have developed methods (or applications) allowing their clients to exchange data packets within a communications network under preferential conditions (or with a certain quality of service level). In order to allow these clients to check (or control) the actual transfer conditions of data of “stream” type, in particular dedicated to video and voice, and transported, for example, according to the RTP protocol (Real-time Transfer Protocol), the RTCP protocol (Real-time Transfer Control Protocol) is used. This protocol, developed for controlling the real-time transfer of data (especially audio and/or video), allows in particular the sender of a stream to receive, in real time, information characterising the data transfer, such as the percentage of data packets lost, or the variation in packet transmission time. The RTP protocol encapsulates the data, numbers and timestamps the packets, and RTCP packets are sent back by the receiver of the RTP stream to the sender, in order to communicate thereto information on the transfer, principally the number of RTP packets lost.
Users, who have possibly paid in order to have preferential conditions, can thus, when they are not satisfied, question their operator (or their service provider) in order to obtain explanations, or discounts. However, in the case of micro-streams (or data exchanges between two end users), such as for example conventional video sessions on the Internet, operators find it difficult to access (in real time or off-line) statistics relating to the quality of the communication, so that they cannot know that a quality problem has appeared, and therefore cannot react in an appropriate manner (possibly disproving the complainant).
The aim of the invention is therefore to remedy this drawback.